91117845589491 has 16 divisors (see below), whose sum is σ = 154273600998400. Its totient is φ = 52067340336744.

The previous prime is 91117845589489. The next prime is 91117845589517. The reversal of 91117845589491 is 19498554871119.

91117845589491 is a `hidden beast` number, since 9 + 1 + 1 + 1 + 7 + 8 + 4 + 55 + 89 + 491 = 666.

It is not a de Polignac number, because 91117845589491 - 2¹ = 91117845589489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91117845589291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241052501371 + ... + 241052501748.

It is an arithmetic number, because the mean of its divisors is an integer number (9642100062400).

Almost surely, 2^{91117845589491} is an apocalyptic number.

91117845589491 is a deficient number, since it is larger than the sum of its proper divisors (63155755408909).

91117845589491 is a wasteful number, since it uses less digits than its factorization.

91117845589491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482105003135 (or 482105003129 counting only the distinct ones).

The product of its digits is 130636800, while the sum is 72.

The spelling of 91117845589491 in words is "ninety-one trillion, one hundred seventeen billion, eight hundred forty-five million, five hundred eighty-nine thousand, four hundred ninety-one".